UML

UML

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What Is the UML?

• The Unified Modeling Language (UML) is the successor to the wave of object-oriented analysis and design (OOA&D) methods that appeared in the late '80s and early '90s

• It most directly unifies the methods of Booch, Rumbaugh (OMT), and Jacobson

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• Unified because it …– Combines main preceding OO methods (Booch by Grady Booch, OMT by Jim Rumbaugh and OOSE by Ivar Jacobson)

• Modelling because it is …– Primarily used for visually modelling systems. Many system views are supported by appropriate models

• Language because …– It offers a syntax through which to express modelled knowledge

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Notations and Meta-Models

• The UML, in its current state, defines a notation and a meta-model

• The notation is the graphical stuff you see in models; it is the syntax of the modeling language

• a meta-model: a diagram, usually a class diagram, that defines the notation

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UML Ancestry

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Further (latest) UML Evolution

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UML Partners

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UML components

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UML diagrams

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UML Diagrams

• Use-Case• Class• Object State• Sequence• Collaboration Activity • Component• Deployment

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UML Diagram Philosophy

• Any UML diagram:• Depicts concepts

– as symbols• Depicts relationships between concepts

– as directed or undirected arcs (lines)• Depicts names

– as labels within or next to symbols and lines

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The Main 4 UML Diagrams

• Use-Case• Class• Sequence• State

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The Other 5 UML Diagrams

• Object• Collaboration• Activity• Component• Deployment

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UML Relationships

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Use Case Diagrams

• In addition to introducing use cases as primary elements in software development, Jacobson (1994) also introduced a diagram for visualizing use cases

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• Components: use-cases and actors– a use-case must always deliver a value to an

actor– the aggregate of all use-cases is the system‘s

complete functionality

• Goals:– consolidate system functional requirements– provide a development synchronisation

point– provide a basis for system testing– provide a basic function-class/operation

map

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• The use case itself is drawn as an oval• The actors are drawn as little stick

figures• The actors are connected to the use

case with lines

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UCD Components

UCD Relationships

• Association relationship

• Extend relationship

• Include relationship

• Generalisation relationship

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• Associations• Links actors to their UCs• Use (or include)• Drawn from base UC to used UC, it shows

inclusion of functionality of one UC in another (used in base)

• Extend • Drawn from extension to base UC, it ext-ends

the meaning of UC to include optional behaviour

• Generalisation• Drawn from specialised UC to base UC, it

shows the link of a specialised UC to a more generalised one

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The UML Class Diagram• there are three perspectives you can use in

drawing class diagrams• Conceptual

– If you take the conceptual perspective, you draw a diagram that represents the concepts in the domain under study

• Specification– You often hear the word "type" used to talk about

an interface of a class; a type can have many classes that implement it, and a class can implement many types.

• Implementation – In this view, we really do have classes and we are

laying the implementation bare

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A UML Class

• Properties of class diagrams:- Static model;- Models structure and behaviour;- Used as a basis for other diagrams;- Easily converted to an object diagram

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UML Class Attribute Examples

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Operations

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Constraints on Operations

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Association Examples

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Association by Aggregation

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Roles in Aggregation

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Aggregation and Generalisation

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UML Packages

• The idea of a package can be applied to any model element, not just classes

• Without some heuristics to group classes together, the grouping becomes arbitrary

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Examples of UML Packages andtheir Logical Grouping

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Examples of Relationships between UML Packages

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Examples of UML PackageImportation

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Packaging Steps

1. Set the context2. Cluster classes together based on

shared relationships3. Model clustered classes as a package4. Identify dependency relationships

amongst packages5. Place dependency relationships

between packages

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